A short while back I made the decision to change to 22LR for edc because of the arthritis in my hands.. There is a long thread about that on the forum. As part of that decision I did an enormous amount of research into the advantages and deficiencies of 22 LR. I am referring to research well beyond gun blogs and YouTube. I learned things I had never known.

One thing that could easily be the cause of the tumble is the relationship of barrel length, powder charge, and bullet weight. Here is how I think that could apply in this case.

We know that velocity is critical to bullet path and performance. We also know that to gain full velocity a bullet must be in the barrel long enough to get a full powder burn but much longer as it will diminish velocity. So barrel length is always a factor in shooting. But we don't often think about bullet weight in that equation.

I learned that from a handgun with say a 3.5 inch barrel a 40gr bullet might fly perfectly true to the target, but a sixty grain bullet might not because the powder burn was not adequate in a short barrel to het the spin needed for stability. While that heavier round might be fine in a rifle length barrel or even a 6 inch barrel hand gun, it underperform in a shorter barrel.

This is often exhibited in gel tests of RN 22 LR ammo from handguns. The bullets frequently tumble in the gel because they loose velocity quickly and that means the spinning decreases.

I would therefore suggest that the OP's proublem is directly related to the to one or a combination of the the three factors of barrel length, bullet weight, and velocity achieved out of the barrel.